Donation is a technique where you temporarily cover your open columns underneath, which will subsequently be uncovered by a method that preserves Back-to-Back (e.g., a TSD) to clear the lines. With the recent emphasis on maintaining high stacking efficiency, donations have become an essential technique to incorporate while managing one's stack.
There are several main benefits of using donations.
- It gives you an alternative way to arrange your minos.
- You can preserve the lines underneath. An example would be preserving clean garbage lines with Parapet.
- It leads to cleaner stacks when used appropriately. A good example of this is using Kaidan to fix the parity of your stack. However, it can also lead to worse stacks if misused.
- Each mino fills 4 blocks of your board. Because you're leaving unfilled blocks underneath with donations, this also means that you need fewer pieces when trying to build the T-spin shape.
This page is an overview of donation techniques.
Step 1. Picture how you would make the base and overhang for the T-Spin.
When doing this, it's important to think about which lines will be cleared. In this case, it means that you shouldn't fill more than 2 blocks on the column marked red (shown on the second picture below). Otherwise, the hole will remain covered after doing the T-Spin.
Step 2. Look at the queue and see if a donation is possible. If not, see if there's an alternate way to donate by repeating Step 1.
Example queue 1: SIZTO
Example queue 2: ZJLT
Example queue 3: SJITT. We will have to rethink our donation for this sequence.
However, notice how conventional stacking leads to a cleaner stack. This goes back to the point mentioned earlier on how overusing donations can lead to an unstable stack.
Below are donation techniques that have their own name.
This distinction is a technicality. The second image below is a donation because the floating lines are separate from the T slot. The third image below is an air T-Spin because the T slot itself is floating.
A shape can be both an air T-Spin and a donation: